Fig. 7
 A bar graph indicating the fluctuating cellular levels of the glutathionyl-S-caffeoylquinic acid conjugate, a discriminatory marker in the changing metabolome of tomato leaves responding to flagellin-derived peptides. A The relative abundance of glutathionyl-S-caffeoylquinic acid after Flg22 (Flg) and FlgII-28 (FlgII) treatments at the 16 h (blue), 24 h (purple) and 32 h time (orange) time intervals. A MgSO4 control (MgSO - grey) was included for each time point. Each data bar is presented as a mean value (\(\stackrel{-}{x}\) of n = 3 × 3 = 9 samples) with the error bars indicating the calculated standard deviation (σ). A two-condition paired Student’s t-test was performed to compare the treatments with the MgSO4 control where the asterisks indicate levels of statistical significance (* = P ≤ 0.01, ** = P ≤ 0.001, *** = P ≤ 0.0001). B The chemical structure of the putatively annotated glutathionyl-S-caffeoylquinic acid conjugate